读入所有可能的角色，或硬编码一个列表.然后运行 ​​isUserInRole 对其进行迭代并构建用户所在角色的列表，然后将该列表转换为数组.

Read in all the possible roles, or hardcode a list. Then iterate over it running the isUserInRole and build a list of roles the user is in and then convert the list to an array.

String[] allRoles = {"1","2","3"};
HttpServletRequest request = ... (or from method argument)
List userRoles = new ArrayList(allRoles.length);
for(String role : allRoles) {
 if(request.isUserInRole(role)) { 
  userRoles.add(role);
 }
}

// I forgot the exact syntax for list.toArray so this is prob wrong here
return userRoles.toArray(String[].class);